Neural network working properly on Matlab but not in Simulink

Hello,

I have trained a NARX type neural network using the NNTOOL tool and when I simulate the network for a given input in Matlab using the command

output=sim(net,input)

I get a satisfactory result.

The problem is that when transferring the network to Simulink using the command

gensim(net,ts)

I obtain a model that does not give good results in Simulink, the output signals being very different from what they should be.

What am I doing wrong when transferring the net to a Simulink block so it doesn't work well ?

Thanks in advance.

[Kanchan Jha]

have you got the solution? i am having the same problem.

Answer 1

[Tarunbir Gambhir]

Please see the documentation page for gensim. When giving a parameter for 'SampleTime', its value may be -1 or any integer greater or equal to 1. However, this may override the default sample time of the trained model and lead to differences in the simulation result.

If you explicitly define the sample time, you should be able to see exactly the same output from MATLAB and Simulink.

[Haritz Odriozola Olalde]

Hi Tarunbir,

I have read the gensim documentation page and it does not appear anywhere that the sampling time must be an integer. In fact, we have tried entering st=0.00025 and it works. Still, we have found where the problem was, so thank you very much for your answer.

Regards

[akram]

Hello, I have exactely the same problem, did you find the solution ?